The software of medical appliances needs to comply with safety guidelines that are stored in DIN standard EN 62304. In this case, the software used for controlling the medical appliances is divided into three classes. Thus, a piece of software that is used directly to control a part of the medical appliance is classified as class C if a malfunction in the software would result in death of or severe injury to the person that is to be treated. If a malfunction would lead to the person to be treated sustaining an injury, but one that is not severe, then the software is classified according to class B. If the part of the medical appliance that is controlled using the software does not pose any risk to the person who is to be treated, this is classified as class A. Depending on the classified class, it is necessary for the software to comply with particular stipulations and also tests. Thus, class B requires documentation and testing of the software, whereas class C requires comparatively extensive documentation of the software and also comparatively extensive testing.
Therefore, if a piece of software is classified as class C, addition of particular further functions or adjustment to suit customer requirements necessitates a comparatively complex review process for the control unit of the medical appliance. This is also the case if the adjustment merely relates to a comparatively noncritical region of the software classified as class C. Consequently, such adjustment is comparatively time-consuming and costly in this case too.